Question

Calculate the period of a ball tied to a string of length 1.45 m making 3.2 revolutions every second. answer in units of s. your answer must be within ± 2.0%

Answer 1

Length of the string L =1.45 m; Frequency F = 3.2 rps.
  The movement would be in circular motion and we have an equation with time period and frequency that is
  F = 1 / T => T = 1 / F
 So T = 1 / 3.2 = 0.3125 sec
 Time Period = 0.3125 s